Creating a civil society is a task that requires sustained effort at the level of the whole community, at the level of institutions (e.g., schools), families, and individuals. Violence can be triggered by failures and deficiencies at any or all of these levels. A "bioecological" model is needed to trace the development of youth violence. Many of the components of violent behavior, such as aggression, are very common early in life, but it takes time and "canalization" for the normally aggressive behavior of most preschoolers to turn into the socially deviant violence of a few adults. The problem for prevention science is to identify both the developmental stage and the bioecological level at which intervention will be most cost-efficient. The Principal Investigator and colleagues have for the past 9 years been conducting two ongoing longitudinal studies that provide unique data sets for identifying key points for intervention in risk for violence. Together they provide data on some 2,300 young people aged 9 through 20, with over 10,000 subject x interview observation points over time. Participants are of both sexes, and include White, African American, and American Indian youth. We request funds to complete the bioecological picture of changing risk for violence by collecting and integrating information on the schools and communities in which the participants are growing up, and using the combined data to identify cost-efficient entry points for intervention. (1) Using tapes provided by the state's Department of Public Instruction, to extract information on the level of violence in each of the schools attended by participants. (2) To identify the "subjective neighborhoods" in which study participants live, and to describe their perceived characteristics. (3) To attach to each participant's file measures of community resources and social capital, ethnic mix, population growth, etc., and also local crime and violence. (4) To check the local juvenile court records for all study participants. Also, to search the NC criminal records on families (and participants over 17 or if waived to adult court). (5) To collect information needed to estimate the cost of services delivered to both violent and nonviolent youth. (6) To model the onset of violence in individuals and groups of participants in terms of the interplay of community, school, family, and individual risk and protective factors over time. (7) To test the hypothesis that violence is explained by a "social selection" model in White, but not minority, children.